title: Patronin mediates a switch from kinesin-13-dependent poleward flux to anaphase B spindle elongation.
abstract: Anaphase B spindle elongation contributes to chromosome segregation during Drosophila melanogaster embryo mitosis. We propose that this process is driven by a kinesin-5-generated interpolar microtubule (MT; ipMT) sliding filament mechanism that engages when poleward flux is turned off. In this paper, we present evidence that anaphase B is induced by the minus end-stabilizing protein patronin, which antagonizes the kinesin-13 depolymerase KLP10A at spindle poles, thereby switching off the depolymerization of the minus ends of outwardly sliding ipMTs to suppress flux. Although intact cortices, kinetochore MTs, and midzone augmentation are dispensable, this patronin-based change in ipMT minus-end dynamics is sufficient to induce the elongation of spindles capable of separating chromosomes.
authors.affiliation: Department of Molecular and Cell Biology, University of California, Davis, Davis, CA 95616.
authors.forename: Haifeng
authors.initials: H
authors.lastname: Wang
authors.forename: Ingrid
authors.initials: I
authors.lastname: Brust-Mascher
authors.forename: Gul
authors.initials: G
authors.lastname: Civelekoglu-Scholey
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Scholey
mesh_terms: D000705:Anaphase; D000818:Animals; D020090:Chromosome Segregation; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000196:embryology / Q000201:enzymology* / Q000235:genetics; D018507:Gene Expression Regulation, Developmental; D049452:Green Fluorescent Proteins / Q000378:metabolism; D016547:Kinesins / Q000235:genetics / Q000378:metabolism*; D007700:Kinetics; D018386:Kinetochores / Q000201:enzymology; D008856:Microscopy, Fluorescence; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism*; D008870:Microtubules / Q000201:enzymology; D008938:Mitosis; D008954:Models, Biological; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D008941:Spindle Apparatus / Q000201:enzymology*
chemical_list: D029721:Drosophila Proteins; D008869:Microtubule-Associated Proteins; D011993:Recombinant Fusion Proteins; C553301:patronin protein, Drosophila; D049452:Green Fluorescent Proteins; C481339:KLP10A protein, Drosophila; D016547:Kinesins